Swollen Knee


What is knee swelling?

Swelling in the knees is a common problem with many possible causes. Knee joints are complicated structures with a number of parts that can cause pain, including:

  • Bones
  • Tendons, which connect muscles and bones
  • Ligaments, which connect bones to other bones
  • Cartilage, which covers the ends of bones and cushions them from each other

Knees have a heavy workload in our lives and bear our weight much of the time. Many kinds of injuries, arthritis, and other problems caused by repetitive use can lead to swelling, an accumulation of fluid in a particular part of the body.

Possible Causes

How is the cause of knee swelling diagnosed?

Your doctor will ask you questions about your pain. These may include:

  • What is the exact location of the pain – the front of the knee, the back, the inside, the outside, above or below the kneecap?
  • Do you feel better or worse at certain times of day?
  • Does it hurt more when you’re walking up or down stairs?
  • How does it hurt? Is it a dull ache or a sharp, stabbing pain?
  • Is the knee range of motion decreased?

Along with these questions your doctor will physically examine the knee and afterward suggest the next step in terms of diagnosing the exact problem. You may have a blood test or fluid taken from the knee with a needle for lab examination. Imaging tests may also be used to diagnose your condition.

Care and Treatment

How is knee swelling treated?

Depending on the type and severity of your problem, treatments range from surgery to home remedies. Non-surgical remedies include:

  • RICE: an abbreviation for “Rest, Ice, Compression and Elevation,” is best to do shortly after suffering an injury. RICE can be helpful for managing minor pain.
  • Compression: wrapping the knee – not too tightly – in an elastic bandage (available at any drug store)
  • Physical therapy: doing exercises to strengthen the knee and improve its stability
  • Wearing a brace on the knee
  • Taking over-the-counter pain-relief medication
  • If you are overweight, losing weight to reduce pressure on the knee

In some cases pain medication or a lubricating substance might be injected into the knee. Or a needle may be used to reduce swelling by removing excess fluid.

What if I need surgery on my swollen knee?

Depending on your situation, surgery can range from arthroscopic surgery to replacing the knee joint with an artificial one.

Arthroscopic surgery uses a tiny camera that is part of an instrument called an arthroscope. It can be used as a tool for diagnosis as well as for treatment, and is usually an outpatient procedure (no overnight hospital stay). Depending on the type of surgery, physician therapy is often recommended afterward to restore mobility and strength in your knee.

Last reviewed by a Cleveland Clinic medical professional on 01/03/2018.


  • American Academy of Orthopaedic Surgeons. Common Knee Injuries. (https://orthoinfo.aaos.org/en/diseases--conditions/common-knee-injuries) Accessed 11/18/2021.
  • Arthritis Foundation. Knee Surgery. (http://www.arthritis.org/about-arthritis/where-it-hurts/knee-pain/treatment/knee-surgery.php) Accessed 11/18/2021.
  • American Academy of Family Physicians. Knee Problems (Symptom Checker). (https://familydoctor.org/symptom/knee-problems/?adfree=true#tray-2) Accessed 11/18/2021.
  • Journal of the Royal Society of Medicine. The Acute Swollen Knee: Diagnosis and Management. (http://journals.sagepub.com/doi/abs/10.1177/0141076813482831) Accessed 11/18/2021.

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